Turbine assembly, hydrokinetic torque converter, and methods for making the same

ABSTRACT

A method of making a turbine assembly for a hydrokinetic torque converter includes providing a first turbine component including a polymeric first turbine shell element and first turbine blades connected to the first turbine shell element, providing a second turbine component including a second turbine shell element and second turbine blades connected to the second turbine shell element, and connecting the first turbine shell element to the second turbine shell element to collectively provide a turbine shell of the turbine assembly and fixedly secure the first and second turbine components to one another in a coaxial relationship about the rotational axis. The connecting involves welding and/or adhesive bonding the first turbine shell element to the second turbine shell element. A turbine assembly, a hydrokinetic torque converter, and a method of making a hydrokinetic torque converter are also provided.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention generally relates to coupling devices, andpreferably to turbine assemblies for hydrokinetic torque converters,hydrokinetic torque converters including the turbine assemblies, andmethods of making and using the same.

2. Background of the Invention

Typically, a hydrokinetic torque converter includes an impellerassembly, a turbine assembly, and a stator assembly (or reactor). Thestator assembly typically includes a one-way clutch for restrictingrotational direction. The turbine assembly is operatively connected,such as by using fasteners or by integral connection, with an output (orturbine) hub that is linked in rotation to a driven shaft, whichoperates as or is linked in rotation to an input shaft of a transmissionof a vehicle. The casing of the torque converter generally includes afront cover and an impeller shell, which together define a fluid filledchamber. Impeller blades are fixed to an impeller shell within the fluidfilled chamber to define the impeller assembly. The turbine assembly andthe stator are also disposed within the chamber, with both the turbineassembly and the stator being relatively rotatable with respect to thefront cover and the impeller shell. The turbine assembly includes aturbine shell with a plurality of turbine blades fixed to one side ofthe turbine shell facing the impeller blades of the impeller.

The turbine assembly works together with the impeller assembly, which islinked in rotation to the casing that is itself linked in rotation to adriving shaft driven by an internal combustion engine. The stator isinterposed axially between the turbine assembly and the impellerassembly.

Conventionally, the turbine shell and the turbine blades are usuallyformed by stamping from steel blanks. The turbine shell is typicallyslotted to receive, through the slots, tabs of the turbine blades. Afterthe turbine blades are located within the turbine shell, the turbineblade tabs are bent or rolled over to form mechanical attachments to theturbine shell. A brazing process is typically carried out to secure theturbine blades fixed in position.

Current hydrokinetic torque converters and methods for assembly thereofmay be complex, cumbersome and expensive. Therefore, while conventionalhydrokinetic torque converters, including but not limited to thosediscussed above, have proven to be acceptable for vehicular drivelineapplications and conditions, improvements that may enhance theirperformance and cost are possible.

BRIEF SUMMARY OF THE INVENTION

A first aspect of the invention provides a method of making a turbineassembly for a hydrokinetic torque converter. The method includesproviding a first turbine component including a polymeric first turbineshell element and first turbine blades connected to the first turbineshell element, providing a second turbine component including a secondturbine shell element and second turbine blades connected to the secondturbine shell element, and connecting the first turbine shell element tothe second turbine shell element to collectively provide a turbine shellof the turbine assembly and fixedly secure the first and second turbinecomponents to one another in a coaxial relationship about the rotationalaxis. The connecting involves welding and/or adhesive bonding the firstturbine shell element to the second turbine shell element.

According to a second aspect of the present invention, a turbineassembly for a hydrokinetic torque converter is provided. The turbineassembly includes a first turbine component including a polymeric firstturbine shell element and first turbine blades connected to the firstturbine shell element, and a second turbine component including a secondturbine shell element and second turbine blades connected to the secondturbine shell element. The first turbine shell element is fixedlysecured by a connection to the second turbine shell element in a coaxialrelationship to collectively provide a turbine shell of the turbineassembly. The connection comprises a weld, an adhesive bond, or acombination comprising a weld and an adhesive bond.

A third aspect of the present invention provides a method of making ahydrokinetic torque converter. The method includes providing a firstturbine component including a polymeric first turbine shell element andfirst turbine blades connected to the first turbine shell element,providing a second turbine component including a second turbine shellelement and second turbine blades connected to the second turbine shellelement, and connecting the first turbine shell element to the secondturbine shell element to collectively provide a turbine shell of theturbine assembly and fixedly secure the first and second turbinecomponents to one another in a coaxial relationship about the rotationalaxis. The connecting involves welding and/or adhesive bonding the firstturbine shell element to the second turbine shell element. The turbineassembly is operatively secured to an impeller including an impellershell whereby the turbine assembly is coaxially aligned with andhydro-dynamically drivable by the impeller assembly. The turbineassembly is operatively connected to a turbine hub. A torsionalvibration damper is operatively connected to the turbine hub and to alockup clutch that is movable into and out of locking engagement with acasing of the hydrokinetic torque converter, wherein the casing isnon-rotatable relative to the impeller shell.

Other aspects of the invention, including apparatus, devices, systems,converters, processes, and the like which constitute part of theinvention, will become more apparent upon reading the following detaileddescription of the exemplary embodiments.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

The accompanying drawings are incorporated in and constitute a part ofthe specification. The drawings, together with the general descriptiongiven above and the detailed description of the exemplary embodimentsand methods given below, serve to explain the principles of theinvention. The objects and advantages of the invention will becomeapparent from a study of the following specification when viewed inlight of the accompanying drawings, in which like elements are given thesame or analogous reference numerals and wherein:

FIG. 1 is a half view in axial section of a hydrokinetic torqueconverter with a turbine assembly in accordance with a first exemplaryembodiment of the present invention;

FIG. 2 is a half view in axial section of the turbine assembly of thehydrokinetic torque converter shown in FIG. 1;

FIG. 3 is an enlarged view of a fragment the turbine assembly shown inthe box III of FIG. 2;

FIG. 4 is a perspective view of a component of the turbine assembly ofthe hydrokinetic torque converter of FIG. 1;

FIG. 5 is an enlarged view of a fragment of the turbine assemblycomponent shown in circle V of FIG. 4;

FIG. 6 is a side sectional view of the turbine assembly of the firstexemplary embodiment shown in a pre-assembled state;

FIG. 7 is a full view in axial section of the turbine assembly of FIG. 6in an assembled yet pre-welded state;

FIG. 8 is an enlarged view of a fragment of the turbine assembly shownin the box VIII of FIG. 7;

FIG. 9 is a side perspective view of a component of the turbine assemblyof the first exemplary embodiment in a preassembled and pre-weldedstate;

FIG. 10 is an enlarged view of a fragment of the turbine assemblycomponent shown in circle X of FIG. 9;

FIG. 11 is an opposite side perspective view of the turbine assemblycomponent of FIG. 9;

FIG. 12 is a side perspective view of another component of the turbineassembly of the first exemplary embodiment of the invention in apreassembled and pre-welded state;

FIG. 13 is a sectional fragmented view of a modification of the firstexemplary embodiment that may be practiced in combination with each ofthe embodiments described herein;

FIG. 14 is a half view in axial section of a hydrokinetic torqueconverter with a turbine assembly in accordance with a second exemplaryembodiment of the present invention;

FIG. 15 is a half view in axial section of the turbine assembly of thehydrokinetic torque converter shown in FIG. 14;

FIG. 16 is an enlarged view of a fragment the turbine assembly shown inthe box XVI of FIG. 15;

FIG. 17 is a perspective view of a component of the turbine assembly ofthe hydrokinetic torque converter of FIG. 14;

FIG. 18 is an enlarged view of a fragment of the turbine assemblycomponent shown in circle XVIII of FIG. 17;

FIG. 19 is a side sectional view of the turbine assembly of the secondexemplary embodiment shown in a pre-assembled state;

FIG. 20 is a full view in axial section of the turbine assembly of FIG.19 in an assembled yet pre-welded state;

FIG. 21 is an enlarged view of a fragment of the turbine assembly shownin the box XXI of FIG. 20;

FIG. 22 is a side perspective view of a component of the turbineassembly of the second exemplary embodiment in a preassembled andpre-welded state;

FIG. 23 is an enlarged view of a fragment of the turbine assemblycomponent shown in circle XXIII of FIG. 22;

FIG. 24 is an opposite side perspective view of the turbine assemblycomponent of FIG. 23;

FIG. 25 is a side perspective view of another component of the turbineassembly of the second exemplary embodiment of the invention in apreassembled and pre-welded state;

FIG. 26 is a half view in axial section of a turbine assembly of ahydrokinetic torque converter in accordance with a third exemplaryembodiment of the present invention, the turbine assembly includingturbine components illustrated in a pre-assembled and pre-welded state;

FIG. 27 is a sectional side view of the turbine components of theturbine assembly of FIG. 26 in an assembled and welded state;

FIG. 28 is an enlarged view of a fragment shown in box XXVIII of FIG.27;

FIG. 29 is a half view in axial section of a turbine assembly of ahydrokinetic torque converter in accordance with a fourth exemplaryembodiment of the present invention, the turbine assembly includingturbine components illustrated in a pre-assembled and pre-welded state;

FIG. 30 is a sectional side view of the turbine components of theturbine assembly of FIG. 29 in an assembled and welded state; and

FIG. 31 is an enlarged view of a fragment shown in box XXXI of FIG. 30.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S) AND EMBODIED METHOD(S)OF THE INVENTION

Reference will now be made in detail to exemplary embodiments andmethods of the invention as illustrated in the accompanying drawings, inwhich like reference characters designate like or corresponding partsthroughout the drawings. It should be noted, however, that the inventionin its broader aspects is not limited to the specific details,representative devices and methods, and illustrative examples shown anddescribed in connection with the exemplary embodiments and methods.

This description of exemplary embodiments is intended to be read inconnection with the accompanying drawings, which are to be consideredpart of the entire written description.

A first exemplary embodiment of a hydrokinetic torque coupling device isgenerally represented in FIG. 1 by reference numeral 10. Thehydrokinetic torque coupling device 10 is configured and intended tocouple a driving shaft and a driven shaft, for example of a motorvehicle, to one another. In the case of such a motor vehicle, thedriving shaft is typically an output shaft of an internal combustionengine (not shown) of the motor vehicle and the driven shaft istypically connected to an automatic transmission (not shown) of themotor vehicle.

The hydrokinetic torque coupling device 10 comprises a sealed casing 12and a hydrokinetic torque converter 14, each rotatable about arotational axis X. The casing 12 is filled with a fluid, such as oil ortransmission fluid. A lock-up clutch 15 and a torsional vibration damper(also referred to herein as a damper assembly) 16 are situated in thecasing 12. The torsional vibration damper assembly 16 and the torqueconverter 14 are mounted on an output (turbine) hub 28, as discussed ingreater detail below. The sealed casing 12, the torque converter 14, thelock-up clutch 15, and the torsional vibration damper 16 are allrotatable about the rotational axis X. Most of the drawings discussedherein show half-views, that is, a cross-section of the portion orfragment of the hydrokinetic torque coupling device 10 above therotational axis X. Hereinafter the axial and radial orientations areconsidered with respect to the rotational axis X of the hydrokinetictorque coupling device 10. Relative terms such as “axially,” “radially,”and “circumferentially” are with respect to orientations parallel to,perpendicular to, and circularly around the rotational axis X,respectively.

The sealed casing 12 according to the first exemplary embodiment asillustrated in FIG. 1 includes a first casing shell 17, and a secondcasing shell 18 disposed coaxially with and axially opposite to thefirst casing shell 17. The first and second casing shells 17 and 18 arenon-movably (i.e., fixedly relative to one another) interconnected andsealed together about their outer peripheries, such as by weld 19. Thesealed casing 12 is non-movably (i.e., fixedly) connected to the drivingshaft, more typically to a flywheel (not shown) that is non-rotatablyfixed to the driving shaft, so that the casing 12 turns at the samespeed at which the engine operates for transmitting torque.Specifically, the casing 12 is rotatably driven by the internalcombustion engine by fixedly coupling the casing 12 to the flywheel ofthe engine, such as by using studs (not shown). Typically, the studs arefixedly secured, such as by welding, to the first casing shell 17. Eachof the first and second casing shells 17 and 18 is integral or aone-piece member. The shells 17 and 18 each can be made, for example, bypress-forming a metal sheet.

The torque converter 14 includes an impeller assembly (sometimesreferred to as the pump or impeller wheel) 20, a turbine assembly(sometimes referred to as the turbine wheel) 22, and a stator assembly(sometimes referred to as the reactor) 24 interposed axially betweenradially inner portions of the impeller assembly 20 and the turbineassembly 22. The impeller assembly 20, the turbine assembly 22, and thestator assembly 24 are coaxially aligned with one another about therotational axis X. The impeller assembly 20, the turbine assembly 22,and the stator assembly 24 collectively form a torus. In operation, theimpeller assembly 20 and the turbine assembly 22 are fluidly (orhydrodynamically) coupled to one another as is known in the art.

The torque coupling device 10 also includes a substantially annularturbine (or output) hub 28 (FIGS. 1 and 13) rotatable about therotational axis X. The turbine hub 28 is configured to couple the drivenshaft (not shown) and the turbine assembly 22 to one another so that thedriven shaft and the turbine assembly 22 are non-rotatable relative toone another. For example, the turbine hub 28 may include splines orteeth for engaging complementary splines or teeth of the driven shaft. Asealing member 29, mounted to a radially inner peripheral surface of theturbine hub 28, is configured to create a seal at the interface of thedriven (transmission input) shaft and the turbine hub 28.

The impeller assembly 20 includes a substantially annular, semi-toroidal(concave) impeller shell 21, a substantially annular impeller core ring26, and a plurality of impeller blades 25 fixedly (i.e., non-moveably)attached, such as by brazing, to the impeller shell 21. A portion of thesecond casing shell 18 of the casing 12 also forms and serves as theimpeller shell 21 of the impeller assembly 20. Accordingly, the impellershell 21 sometimes is referred to as part of the casing 12 with respectto exemplary embodiments. The impeller assembly 20, including theimpeller shell 21, the impeller core ring 26, and the impeller blades25, is non-rotatably secured to the first casing shell 17 by the weld19, and hence to the drive shaft (or flywheel) of the engine to rotateat the same speed as the engine output. The impeller shell 21, theimpeller blades 25, and the impeller core ring 26 may be conventionallyformed by stamping from steel blanks. Alternatively, the impeller shell21, the impeller blades 25, and/or the impeller core ring 26 may bemolded from one or more polymeric materials, for example, by practicinginjection molding. The impeller shell 21 and blades 25 may be molded asa single integral piece.

The turbine assembly 22 includes a substantially annular turbine shell30 rotatable about the rotational axis X, and pluralities of radiallyouter turbine blades 40 and radially inner turbine blades 48 fixedly(i.e., non-moveably) secured to the turbine shell 30. The turbine blades48 face the impeller blades 25 of the impeller assembly 20. The turbineshell 30 includes a radially inner, substantially annular mountingportion 44 with circumferentially spaced mounting holes 45 for receivingmechanical fasteners, such as rivets 27, to non-movably (i.e., fixedly)secure the turbine assembly 22 to the turbine hub 28.

The stator assembly 24 includes a substantially annular stator hub 23coaxial to the rotational axis X, a substantially annular turbine corering 33 also coaxial to the rotational axis X and located radiallyoutside the stator hub 23, and a plurality of stator blades 31interconnecting the stator hub 23 and the turbine core ring 33. Theturbine core ring 33 is curved in a semi-toroidal cross-section andfaces the impeller core ring 26. The turbine core ring 33 of the statorassembly 24 has an inner concave surface facing the impeller core ring26 and an opposite outer convex surface facing and spaced from theturbine blades 40 and 48. The turbine core ring 33 may be formed at theradially outer ends of the stator blades 31. In particular, the statorhub 23, the turbine core ring 33, and the stator blades 31 may be formedas a single integral piece by molding, e.g., injection mold, a polymermaterial.

The turbine assembly 22 includes an outer turbine component 34 and aninner turbine component 36 arranged coaxial with one another androtatable about the rotational axis X. The outer turbine component 34preferably is a separately formed from the inner turbine component 36,and later connected to the inner turbine component 36 so that theturbine components 34 and 36 are secured non-moveably relative to oneanother. The outer turbine component 34 has an outer radius (ordiameter) that is larger than an outer radius (or diameter) of the innerturbine component 36.

The outer turbine component 34 includes a substantially annular outerturbine shell element 38 and a plurality of radially outer turbineblades 40 extending to face toward the impeller blades 25. In apreferred embodiment, the outer turbine shell element 38 is integrallyformed with the radially outer turbine blades 40 as a single or unitary(i.e., one-piece) outer turbine component 34. Alternatively, the outerturbine shell element 38 and the radially outer turbine blades 40 may beseparate components fixedly (i.e., non-moveably relative to one another)connected together. The outer turbine shell element 38 has asubstantially semi-toroidal portion 42 and the substantially annularmounting portion 44 located radially within the substantiallysemi-toroidal portion 42. The mounting portion 44 of the outer turbineshell element 38 is provided with the plurality of equiangularcircumferentially spaced mounting holes 45, as best shown in FIGS. 2,12, and 13. The mounting holes 45 are circumferentially equiangularlyspaced. Fasteners such as rivets 27 extending through the mounting holes45 fixedly secure the outer turbine shell element 38 to the turbine hub28.

In a modified embodiment illustrated in FIG. 13, each of the mountingholes 45 is circumscribed by a grommet 50. The grommets 50 are mountedto the mounting portion 44 of the outer turbine shell element 38 aroundthe mounting holes 45 as a reinforcement, so that each of the rivets 27axially extends through an opening 51 in one of the grommets 50 in orderto non-movably (i.e., fixedly) secure the turbine shell 30 of theturbine assembly 22 to the turbine hub 28. Each of the grommets 50includes a cylindrical portion 52, and two axially opposite annularflanges 54 ₁ and 54 ₂ extending radially outwardly from the cylindricalportion 52 of the grommet 50. A central axis C of the cylindricalportion 52 is substantially parallel to the rotational axis X. Theflanges 54 ₁ and 54 ₂ of the grommet 50 are axially spaced from eachother to provide a gap therebetween for receiving the mounting portion44 of the outer turbine shell element 38 around the mounting holes 45.The mounting portion 44 of the outer turbine shell element 38 issandwiched between the annular flanges 54 ₁ and 54 ₂ of the grommet 50so that the annular flanges 54 ₁ and 54 ₂ engage axially opposite sidesof the mounting portion 44 of the outer turbine shell element 38. Thegrommets 50 may be made of a rigid material, such as metal, plastic orpolymer. For example, the grommets 50 may be made of steel, such as SAE1020 carbon steel, which has a good combination of strength andductility and may be hardened or carburized, and is readily cold workedby conventional methods. The outer turbine component 34 may be made of apolymer molded around the outer periphery of the grommets 50.Alternatively, grommet installation tools, which are known in the art,may be used, particularly if the outer turbine component is made ofmetallic material such as aluminum or magnesium alloys.

The inner turbine component 36 preferably is formed separately from theouter turbine component 34. The inner turbine component 36 includes asubstantially annular inner turbine shell element 46 and a plurality ofradially inner turbine blades 48. The radially inner turbine blades 48preferably are integral with and extend from an annular, substantiallysemi-toroidal (concave) inner surface of the inner turbine shell element46 so as to face toward the impeller blades 25 of the impeller assembly20. Preferably, the inner turbine shell element 46 and the radiallyinner turbine blades 48 are made as a single or unitary (i.e.,one-piece) component. Alternatively, the inner turbine shell element 46and the radially inner turbine blades 48 may be separate componentsfixedly (i.e., non-moveably relative to one another) connected together.

In the first exemplary embodiment, at least a portion of the innerturbine shell element 46 is made of a polymeric material. The polymericmaterial may be molded into form using any suitable technique,including, for example, injection molding. In the first exemplaryembodiment, the outer turbine component 34 and/or the remainder of theinner turbine component 36 may be made of metal or polymer. It isparticularly advantageous to mold or otherwise shape the turbinecomponents 34 and 36 into unitary polymeric components in order toremove the need for brazing processes practiced in connection withmetallic components that slow and complicate production.

The outer and inner turbine components 34 and 36 are fixedly connectedto one another to provide the turbine assembly 22. In a preferredembodiment, the outer and inner turbine shell elements 38 and 46 areassembled and fixedly connected via welding, adhesive bonding, or acombination including at least welding and adhesive bonding tocollectively establish the turbine shell 30 of the turbine assembly 22.

Welding, particularly ultrasonic welding, is preferred for connectingthe inner and outer turbine shell elements 38 and 46 to one another,especially when the elements 38, 46 are formed of a polymeric material.Generally, ultrasonic welding involves application of high-frequencyultrasonic acoustic vibrations to local areas (described below) of theturbine shell elements 38 and 46 being held together, typically with theapplication of pressure, to create a solid-state weld. Althoughultrasonic welding is principally described herein in connection withthe first exemplary embodiment and other exemplary embodiments, itshould be understood that other techniques may be practiced to connectthe inner and outer turbine shell elements 38 and 46 to one another in afixedly secure manner, including for example laser welding, frictionspot welding, and/or adhesive bonding. In a preferred weldingembodiment, no mechanical fasteners, soldering materials, or adhesivesare necessary or used to connect the welded inner and outer turbineshell elements 38 and 46 together.

FIG. 3 shows local areas of radially overlapping portions of the innerand outer turbine shell elements 38 and 46 at which ultrasonic weldinghas occurred. The outer turbine shell element 38 includes recessed areas(or recesses) 39, and the inner turbine shell element 46 includes tabs47 received in and solid-state welded to the recessed areas 39. As bestshown in FIG. 4, the tabs 47 may be circumferentially equiangularlyspaced around the rear surface of the inner turbine shell element 46. InFIGS. 4 and 5, the tabs 47 are in pairs of two, with each set of twotabs aligned along a common radial line. Alternatively, three, four, ormore tabs 47 may be aligned together along the same radial line. Asanother alternative, only a single tab 47 may be located along a givenradial line. Each of the tabs 47 is aligned with and received by acorresponding one of the recessed areas 39.

FIGS. 6-12 illustrate the inner and outer turbine components 34 and 36prior to being welded and/or bonded to one another, such as byultrasonic welding. As best shown in FIGS. 6-10, particularly FIG. 10,prior to (ultrasonic) welding the tabs 47 are configured as moldedprotuberances 47A on a side surface of the inner turbine shell element46 facing the outer turbine shell element 38. The protuberances 47A arein corresponding positions to the recesses 39 of the outer turbine shellelement 38 that receive the protuberances 47A. As best shown in FIGS. 8and 10, the protuberances 47A are each embodied in the first exemplaryembodiment as parallel ridges separated by small inverse ridge-like,V-shaped spaces (unnumbered). The protuberances 47A have a thicknessthat is slightly greater than the depth of the recesses 39, so that thefacing surfaces of the overlapping portions of the inner and outerturbine shell elements 38 and 46 are spaced from one another by a smallgap 49 (FIG. 8) prior to welding.

Welding the inner turbine shell element 46 at local areas correspondingto the locations of the protuberances 47A causes the ridges of theprotuberances 47A to soften and optionally melt. Pressure applied toopposite surfaces of the inner and outer turbine shell causes elements38 and 46 to collapse the small gap 49 as the protuberances 47A reshapeinto the tabs 47 to conform to the shape of the recesses 39. The tabs 47are then cooled and harden.

In the first exemplary embodiment, the inner turbine shell element 46,and more preferably the entirety of the inner turbine component 36, ismade of one or more polymers that can be subject to ultrasonic weldingto reshape the protuberances 47A into the tabs 47, as described above.Examples of suitable polymeric materials for the inner turbine component36 are polyetheretherketone (PEEK), such as a carbon-fiber reinforcedgrade PEEK, a commercially available example of which is KetaSpire®KT-880 CF30. Preferably, the inner turbine shell element 46 and theradially inner turbine blades 48 of the inner turbine component 36 areintegrally formed with one another as a single piece. For example, theinner turbine component 36 may be made by a suitable molding process,such as injection molding the inner turbine shell element 46 and theinner turbine blades 48 in a common mold.

In the first exemplary embodiment, the outer turbine component 34 is notsubject to deformation. Accordingly, the outer turbine component 34 maybe made of metal (e.g., aluminum or magnesium alloys) and/or polymericmaterial, such as the PEEK material discussed above. In this manner, thesame or different materials can be selected for the outer turbinecomponent 34 and the inner turbine component 36 to provide the turbinecomponents 34 and 36 with the same or different mechanicalcharacteristics, such as strengths, specific weights, densities, moduliof elasticity, melting points, etc.

As shown by comparing FIGS. 3 and 8, the inner turbine shell element 46is made of a polymeric material in order to allow it to be reshapedand/or reformed in the welding process, particularly at theprotuberances 47A, which are reshaped and/or reformed as the tabs 47that fill and are welded to the recesses 39. On the other hand, theouter turbine shell element 38 is not necessarily reshaped and/orreformed in the welding process, particularly at the recesses 39 thatreceive the protuberances 47A that are welded to form the tabs 47, andthus can be made of metal or polymeric materials.

Molding of the outer and/or inner turbine components 34 and/or 36provides wide latitude in controlling the thickness of the turbinecomponents 34 and/or 36. For example, the outer turbine shell element 38or the inner turbine shell element 46 can have thicknesses that variesat different radial positions. The outer and inner turbine shell element38 and 46 may have thicknesses that differ from the thicknesses of theradially outer and radially inner turbine blades 40 and 48,respectively. The thicknesses of the radially outer turbine blades 40 orthe radially inner turbine blades 48 may vary. The capability to controlthickness provides the possibility for mass optimization by increasingthickness at locations where greater strength is needed and reducingthickness where strength is not needed to thereby reduce the overallweight of the turbine assembly 22. Further, molding provides the optionof providing the molded turbine assembly 22 with molded reinforcingribs.

Referring back to FIG. 1, the torsional vibration damper 16advantageously allows the turbine assembly 22 of the torque converter 14to be coupled, with torque damping, to the input shaft of the automatictransmission.

The torsional vibration damper 16, as best shown in FIG. 1, is disposedbetween the turbine shell 30 and a locking piston 72 of the lock-upclutch 15. The locking piston 72 of the lock-up clutch 15 is rotatablymounted on the turbine hub 28, and is axially moveable on the turbinehub 28 along the rotational axis X. A seal 73 is provided along theinterface of the locking piston 72 and the turbine hub 28. The torsionalvibration damper 16 is arranged on the turbine hub 28 in a limited,movable and centered manner.

The lockup clutch 15 includes a locking piston 72 that is axiallymovably by controlling fluid pressure within the casing 12. Controllinglocking piston movement is known in the art. In a locking position, thelocking piston 72 frictionally engages an inner surface of the firstcasing shell 17, so that the locking piston 72 rotates with the casing12.

The locking piston 72 inputs torque to the torsional vibration damper 16when the device 10 operates in lockup mode. As best shown in FIG. 1, thetorsional vibration damper 16 includes a substantially annular inputmember 60 operatively connected to the locking piston 72 so as to benon-rotatable relative to one another. The annular input member 60includes tabs 60 a that engage ends of radially outer, circumferentiallyextending elastic members 62. The damper 16 further includes anintermediate member 64 having radially outer tabs 64 a engaging ends ofthe elastic members 62. The intermediate member 64 further includesradially inner tabs proximate to 64 b engaging ends of radially inner,circumferentially extending elastic members 66. The elastic members 66elastically couple the intermediate member 64 to an output member 68,which has tabs engaging ends of the elastic members 66. In this setup,the annular input member 60 is rotatably relative to the intermediatemember 64, and the intermediate member 64 is rotatably relative to theoutput member 68 for torsional vibration damping.

When the lock-up clutch 15 is active, i.e., in a closed operativeposition, torque is transferred from the first casing shell 17, to thelocking piston 72, to the annular input member 60, to the radially outerelastic members 62, to the intermediate member 64, to the radially innerelastic members 66, to the output member 68, and to the output hub 28 towhich the output member 68 is fixedly attached by rivets 27. The elasticmembers 62 and 66 provide a damping effect. According to the exemplaryembodiment, the elastic members 62 and 66 are configured as helical (orcoil) springs having a principal axis oriented substantiallycircumferentially. Other elastic members may be selected to replace orsupplement the elastic members 62 and 66.

On the other hand, when the lock-up clutch 15 is inactive, i.e., in anopen operative position, the locking piston 72 is not fictionallyengaged with the first casing shell 17. Torque is hydrokineticallytransferred through the torque converter 14 to the output hub 28, whichis fixedly attached to the turbine assembly 22 by rivets 27.

As best shown in the embodiment of FIG. 13, the output member 68 isprovided with a plurality of equiangular circumferentially spaced holes69. The output member 68 is fixedly (i.e., non-movably) secured to theturbine hub 28 and the mounting portion 44 of the turbine shell 30 bythe rivets 27 extending through the holes 69 in the output member 68,aligned holes (unnumbered) of the turbine hub 28, and the alignedmounting holes 45 of the mounting portion 44.

A method for making the turbine assembly 22 and the hydrokinetic torquecoupling device 10 of the first exemplary embodiment is described below.It should be understood that this exemplary method may be practiced inconnection with the other embodiments described herein. This exemplarymethod is not the only method for assembling the turbine assemblies andhydrokinetic torque coupling devices described herein, and is notexhaustive of possible modifications and variations that may bepracticed. While the methods for assembling the turbine assemblies andhydrokinetic torque coupling devices may be practiced by successivelyperforming the steps as set forth below, it should be understood thatthe methods may involve performing the steps in different sequences, orcombining steps, adding steps not described herein, or eliminating stepsdescribed herein.

As described above, each of the grommets 50 has the cylindrical portion52 and two axially opposite annular flanges 54 ₁ and 54 ₂ extendingradially outwardly from the cylindrical portion 52 of the grommet 50.The outer turbine component 34 may be made by injection molding theplastic material integrally with the grommets 50, thus molding theplastic material over and around the cylindrical portion 52 of thegrommets 50 so as to sandwich the mounting portion 44 of the outerturbine component 34 between the two axially opposite annular flanges 54₁ and 54 ₂ of the grommets 50. Alternatively, a grommet installationtool may be used to attached the grommets 50 to the outer turbinecomponent 34. The inner turbine component 36 preferably is madeseparately from the outer turbine component 34, for example, by moldingplastic.

The inner turbine shell element 46 of the inner turbine component 36 isaxially aligned and non-moveably connected to the outer turbine shellelement 38 of the outer turbine component 34. Preferably, the inner andouter turbine shell elements 46 and 38 are directly connected oneanother by welding, such as ultrasonic welding or friction welding. Asan alternative, the inner and outer turbine shell elements 46 and 38 maybe directly bonded to one another, for example by use of an appropriateadhesive within the recesses 39. The connected turbine shell elements 38and 46 collectively define the turbine shell 30 of the turbine assembly22.

An exemplary method for making the hydrokinetic torque-coupling device10 is as follows.

The impeller assembly 20, the stator assembly 24, and the damperassembly 16 may each be preassembled. Parts of the impeller assembly 20and the stator assembly 24 may be formed, for example, by stamping frommetal (e.g., steel) blanks or injection molding a polymeric material.The turbine assembly 22 is assembled as described above.

The impeller assembly 20, the turbine assembly 22, and the statorsubassembly 24 are assembled together so as to form the torque converter14. The damper assembly 16 and the turbine hub 28 are fastened to themounting portion 44 of the turbine shell 30 of the torque converter 14via the fasteners, e.g., rivets 27. In the modified embodiment of FIG.13, each of the rivets 27 axially extends through the associated opening51 in one of the grommets 50 over-molded in the turbine shell 30. Thelocking piston 72 is fitted about the output hub 28 and radially outertabs of the input member 60 are engaged with the radially outer elasticmembers 62. Then, the first casing shell 17 is non-moveably andsealingly secured, such as by welding at 19, to the second casing shell18, as best shown in FIG. 1.

Various modifications, changes, and alterations may be practiced withthe above-described embodiment, including but not limited to theadditional embodiments shown in FIGS. 14-31. In the interest of brevity,reference characters discussed above in connection with the firstexemplary embodiment of FIGS. 1-12 and the modified embodiment of FIG.13 are not further elaborated upon below, except to the extent necessaryor helpful to explain the additional embodiments of FIGS. 14-31. Whereuseful, modified components and parts of the second, third, and fourthexemplar embodiments are indicated by the addition of 100, 200, and 300hundred digits, respectively, to the reference numerals of thecomponents, parts, or features.

A hydrokinetic torque-coupling device 110 of a second exemplaryembodiment is illustrated in FIGS. 14-25. In the second exemplaryembodiment, a turbine assembly 122 replaces the turbine assembly 22 ofFIGS. 1-13. Other than the substitution of the turbine assembly 122, thehydrokinetic torque coupling device 110 of the second exemplaryembodiment is substantially the same in structure and operation as thehydrokinetic torque coupling device 10 of the first exemplaryembodiment.

The turbine assembly 122 includes an outer turbine component 134 and aninner turbine component 136 coaxial with one another and rotatable aboutthe rotational axis X. The outer turbine component 134 preferably is aseparately formed from and later connected to the inner turbinecomponent 136 so that the turbine components 134 and 136 are securednon-moveably relative to one another. The outer turbine component 134has an outer radius (or diameter) that is larger than an outer radius(or diameter) of the inner turbine component 136.

The outer turbine component 134 includes a substantially annular outerturbine shell element 138 and a plurality of radially outer turbineblades 140 extending to face toward the impeller blades 25. In apreferred embodiment, the outer turbine shell element 138 is integrallyformed with the radially outer turbine blades 140 as a single or unitary(i.e., one-piece) outer turbine component 134. Alternatively, outerturbine shell element 138 and the radially outer turbine blades 140 maybe separate components fixedly (i.e., non-moveably relative to oneanother) connected together. The outer turbine shell element 138 has asubstantially semi-toroidal portion 142 and a substantially annularmounting portion 144 located radially within the substantiallysemi-toroidal portion 142. The mounting portion 144 of the outer turbineshell element 138 is provided with a plurality of equiangularcircumferentially spaced mounting holes 145, as best shown in FIGS. 14,15, and 25. The mounting holes 145 are circumferentially equiangularlyspaced. Fasteners such as rivets 27 extending through the mounting holes145 fixedly secure the outer turbine shell element 138 to the turbinehub 28. Grommets 50 may be used as discussed above, especially inreference to FIG. 13.

The inner turbine component 136 preferably is formed separately from theouter turbine component 134 and includes a substantially annular innerturbine shell element 146 and a plurality of radially inner turbineblades 148. The radially inner turbine blades 148 are integral with andextend from an annular, substantially semi-toroidal (concave) innersurface of the inner turbine shell element 146 so as to face toward theimpeller blades 25 of the impeller assembly 20. Preferably, the innerturbine shell element 146 and the radially inner turbine blades 148 aremade as a single or unitary (i.e., one-piece) component. Alternatively,the inner turbine shell element 146 and the radially inner turbineblades 148 may be separate components fixedly (i.e., non-moveablyrelative to one another) connected together.

In the second exemplary embodiment, at least a portion of the outerturbine shell element 138 is made of a polymeric material. The polymericmaterial may be molded into shape using any suitable technique, such as,for example, injection molding. In the second exemplary embodiment, theinner turbine component 136 and/or the remainder of the outer turbinecomponent 134 may be made of metal or polymer. It is particularlyadvantageous to mold or otherwise shape the turbine components 134 and136 into unitary polymeric components in order to remove the need forbrazing processes that slow and complicate production.

The outer and inner turbine components 134 and 136 are fixedly connectedto one another to provide the turbine assembly 122. In a preferredembodiment, the outer and inner turbine shell elements 138 and 146 areassembled and connected in a fixed (non-movable) connection via welding,adhesive bonding, or a combination including at least welding andadhesive bonding to collectively establish the turbine shell 130 of theturbine assembly 122.

Welding, particularly ultrasonic welding, is preferred for connectingthe outer and inner turbine shell elements 138 and 146 to one another.Generally, ultrasonic welding involves application of high-frequencyultrasonic acoustic vibrations to local areas (described below) of theturbine shell elements 138 and 146 being held together, typically withthe application of pressure, to create a solid-state weld. Althoughultrasonic welding is principally described herein in connection withthe second exemplary embodiment and other exemplary embodiments, itshould be understood that other welding and bonding techniques may bepracticed to connect the outer and inner turbine shell elements 138 and146 to one another in a fixedly secured manner, including for examplelaser welding, friction spot welding, and/or adhesive bonding. In apreferred welding embodiment, no mechanical fasteners, solderingmaterials, or adhesives are necessary or used to connect the weldedturbine shell elements 138 and 146 together.

FIG. 16 shows local areas of radially overlapping portions of the outerand inner turbine shell elements 138 and 146 at which ultrasonic weldinghas occurred. The inner turbine shell element 146 includes recessedareas (or recesses) 139, and the outer turbine shell element 138includes tabs 147 received in and solid-state welded to the recessedareas 139 of the inner turbine shell element 146. As best shown in FIGS.17 and 22, the recessed areas 139 may be circumferentially equiangularlyspaced around the rear surface of the inner turbine shell element 146.In FIGS. 17, 18, 22, and 23, the recessed areas 139 are arranged inpairs of two, with the two recesses aligned along a common radial line.Alternatively, three, four, or more recesses 139 may be aligned togetheralong the same radial line. As another alternative, only a single recess139 may be located along a given radial line. Each of the tabs 147 isaligned with and received by a corresponding one of the recesses 139.

FIGS. 19-25 illustrate the outer and inner turbine components 134 and136 prior to being welded and/or bonded to one another, such as byultrasonic welding. As best shown in FIG. 25, prior to (ultrasonic)welding the tabs 147 are configured as molded protuberances 147A on aside surface of the outer turbine shell element 138 facing the innerturbine shell element 146. The protuberances 147A are in correspondingpositions to the recesses 139 of the inner turbine shell element 146that receive the protuberances 147A. As best shown in FIGS. 21 and 25,the protuberances 147A are each embodied in the second exemplaryembodiment as parallel ridges separated by small inverse ridge-like,V-shaped spaces (unnumbered). The protuberances 147A have a thicknessthat is slightly greater than the depth of the recesses 139, so that thefacing surfaces of the overlapping portions of the outer and innerturbine shell elements 138 and 146 are spaced from one another by asmall gap 149 (FIG. 21) prior to welding.

Welding the outer turbine shell element 138 at local areas correspondingto the locations of the protuberances 147A cause the ridges of theprotuberances 147A to soften and optionally melt. Pressure applied toopposite surfaces of the outer and inner turbine shell causes elements138 and 146 to collapse the small gap 149 and cause the protuberances147A reshape into the tabs 147 to conform to the shape of the recesses139. The tabs 147 are then cooled and harden.

In the second exemplary embodiment, the outer turbine shell element 138,and more preferably the entirety of the outer turbine component 134, ismade of one or more polymers that can be subject to (ultrasonic) weldingto reshape the protuberances 147A into the tabs 147, as described above.Examples of suitable polymeric materials for the outer turbine component134 are polyetheretherketone (PEEK), such as a carbon-fiber reinforcedgrade PEEK, a commercially available example of which is KetaSpire®KT-880 CF30. Preferably, the outer turbine shell element 138 and theradially outer turbine blades 140 of the outer turbine component 134 areintegrally formed with one another as a single piece. For example, theouter turbine component 134 may be made by a suitable molding process,such as injection molding the outer turbine shell element 138 and theradially outer turbine blades 140 in a common mold.

In the second exemplary embodiment, the inner turbine component 136 isnot subject to deformation. Accordingly, the inner turbine component 136may be made of metal (e.g., aluminum or magnesium alloys) and/orpolymeric material, such as the PEEK material discussed above. In thismanner, the same or different materials can be selected for the outerturbine component 134 and the inner turbine component 136 to controlmechanical characteristics, such as strengths, specific weights,densities, moduli of elasticity, melting points, etc.

As shown by comparing FIGS. 16 and 21, the outer turbine shell element138 is made of a polymeric material in order to allow it to be reshapedand/or reformed in the welding process, particularly at theprotuberances 147A, which are reshaped and/or reformed as the tabs 147that fill and are welded to the recesses 139. On the other hand, theinner turbine shell element 146 is not necessarily reshaped and/orreformed in the welding process, particularly at the recesses 139 thatreceive the protuberances 147A that are welded to form the tabs 147, andthus can be made of metal or polymeric materials.

Molding of the outer and/or inner turbine components 134 and/or 136provides wide latitude in controlling the thickness of the turbinecomponents 134 and/or 136. For example, the outer turbine shell element138 or the inner turbine shell element 146 can have thicknesses thatvaries at different radial positions. The outer and inner turbine shellelement 138 and 146 may have thicknesses that differ from thethicknesses of the radially outer and radially inner turbine blades 140and 148, respectively. The thicknesses of the radially outer turbineblades 140 or the radially inner turbine blades 148 may vary. Thecapability to control thickness provides the possibility for massoptimization by increasing thickness at locations where greater strengthare needed and reducing thickness where strength is not needed tothereby reduce the overall weight of the turbine assembly 122. Further,molding provides the option of providing the molded turbine assembly 122with molded reinforcing ribs.

The turbine assembly 122 and hydrodynamic torque coupling device 110 ofthe second exemplary embodiment may be made in accordance with theexemplary methods described above with respect to the first exemplaryembodiment. Notably, the inner turbine shell element 146 of the innerturbine component 136 is axially aligned and non-moveably secured to theouter turbine shell element 138 of the outer turbine component 134 bywelding and/or bonding, such as ultrasonic welding, friction welding,adhesive bonding, etc., so as to collectively define the turbine shell130 of the turbine assembly 122.

A turbine assembly 222 for a hydrokinetic torque-coupling deviceaccording to a third exemplary embodiment is illustrated in FIGS. 26-28.The turbine assembly 222 of the third exemplary embodiment issubstitutable into the hydrokinetic torque coupling devices 10 and 110described above. The primary differences between the turbine assembly222 of the third exemplary embodiment and the turbine assembly 22 of thefirst exemplary embodiment are explained in detail below.

The turbine assembly 222 includes an outer turbine component 234 havingan outer turbine shell element 238 with a substantially semi-toroidalportion 242 and a planar portion 243. Recesses 239 are provided in theplanar radially inner portion 243, compared to the embodiment of FIGS.1-13, in which the recesses 39 are provided in the substantiallysemi-toroidal portion 42. An inner turbine component 236 of the turbineassembly 222 includes an inner turbine shell element 246 havingprotuberances 247A. During assembly, the protuberances 247A are receivedin the recesses 239 of the planar radially inner portion 243 of theouter turbine shell element 238. The turbine assembly 222 is subjectedto a welding or bonding technique, such as described above with respectto the first exemplary embodiment. In connection with welding, theprotuberances 247A reshape and/or reform as tabs 247 in the recesses239, as best shown in FIG. 28.

A turbine assembly 322 for a hydrokinetic torque-coupling deviceaccording to a fourth exemplary embodiment is illustrated in FIGS.29-31. The turbine assembly 322 of the fourth exemplary embodiment issubstitutable into the hydrokinetic torque coupling devices 10 and 110described above. The primary differences between the turbine assembly322 of the third exemplary embodiment and the turbine assembly 122 ofthe second exemplary embodiment are explained in detail below.

The turbine assembly 322 includes an outer turbine component 334 havingan outer turbine shell element 338 with a substantially semi-toroidalportion 342 and a planar radially inner portion 343. Protuberances 347Aare provided on the planar radially inner portion 243, compared to theembodiment of FIGS. 14-25, in which the recesses protuberances 147A areprovided in the semi-toroidal portion 142. An inner turbine component336 of the turbine assembly 322 includes an inner turbine shell element346 having recesses 339 in positions corresponding to the protuberances347A. During assembly, the protuberances 347A of the planar radiallyinner portion 343 of the outer turbine shell element 338 are received inthe recesses 339 of the inner turbine shell element 346. The turbineassembly 322 is subjected to a welding or bonding technique, such asdescribed above with respect to the second exemplary embodiment. Weldingcauses the protuberances 347A to reshape and/or reform as tabs 347 inthe recesses 339, as best shown in FIG. 31.

The various components and features of the above-described exemplaryembodiments may be substituted into one another in any combination. Itis within the scope of the invention to make the modifications necessaryor desirable to incorporate one or more components and features of anyone embodiment into any other embodiment. In addition, although theexemplary embodiments discuss steps performed in a particular order forpurposes of illustration and discussion, the methods discussed hereinare not limited to any particular order or arrangement. One skilled inthe art, using the disclosures provided herein, will appreciate thatvarious steps of the methods can be omitted, rearranged, combined,and/or adapted in various ways.

The foregoing description of the exemplary embodiments of the presentinvention has been presented for the purpose of illustration inaccordance with the provisions of the Patent Statutes. It is notintended to be exhaustive or to limit the invention to the precise formsdisclosed. The embodiments disclosed hereinabove were chosen in order tobest illustrate the principles of the present invention and itspractical application to thereby enable those of ordinary skill in theart to best utilize the invention in various embodiments and withvarious modifications as suited to the particular use contemplated, aslong as the principles described herein are followed. This applicationis therefore intended to cover any variations, uses, or adaptations ofthe invention using its general principles. Further, this application isintended to cover such departures from the present disclosure as comewithin known or customary practice in the art to which this inventionpertains. Thus, changes can be made in the above-described inventionwithout departing from the intent and scope thereof. It is also intendedthat the scope of the present invention be defined by the claimsappended thereto.

1. A method of making a turbine assembly having a rotational axis for ahydrokinetic torque converter, the method comprising: providing a firstturbine component comprising a polymeric first turbine shell element andfirst turbine blades connected to the first turbine shell element;providing a second turbine component comprising a second turbine shellelement and second turbine blades connected to the second turbine shellelement; and connecting the first turbine shell element to the secondturbine shell element to collectively provide a turbine shell of theturbine assembly and fixedly secure the first and second turbinecomponents to one another in a coaxial relationship about the rotationalaxis, said connecting comprising welding, adhesive bonding, or acombination comprising welding and adhesive bonding of the first turbineshell element to the second turbine shell element.
 2. The method ofclaim 1, wherein the first turbine blades are polymeric and integrallyformed with the first turbine shell element.
 3. The method of claim 1,wherein the second turbine blades and the second turbine shell elementare polymeric and integrally formed with one another.
 4. The method ofclaim 1, wherein the second turbine blades and the second turbine shellelement are metallic.
 5. The method of claim 1, wherein the firstturbine shell element and the second turbine shell element have variablethickness portions, and wherein said connecting comprises positioningthe variable thickness portions in radially overlapping relationshipwith one another.
 6. The method of claim 1, wherein the second turbineshell element is positioned farther radially outward than the firstturbine shell element and comprises recesses, wherein the first turbineshell element comprises protuberances, and wherein said connectingcomprises positioning the protuberances in the recesses and reshapingthe protuberances by welding into tabs that are solid-state welded tothe recesses.
 7. The method of claim 6, wherein the recesses arecircumferentially spaced about the second turbine shell element and theprotuberances are circumferentially spaced about the first turbine shellelement in corresponding positions to the recesses.
 8. The method ofclaim 6, wherein the recesses and the protuberances are provided atsubstantially semi-toroidal radially outer portions of the secondturbine shell element and the first turbine shell element, respectively.9. The method of claim 6, wherein the recesses and the protuberances areprovided at planar portions of the second turbine shell element and thefirst turbine shell element, respectively.
 10. The method of claim 1,wherein the first turbine shell element is positioned farther radiallyoutward than the second turbine shell element and comprisesprotuberances, wherein the second turbine shell element comprisesrecesses, and wherein said connecting comprises positioning theprotuberances in the recesses and reshaping the protuberances by weldinginto tabs that are solid-state welded to the recesses.
 11. The method ofclaim 10, wherein the protuberances are circumferentially spaced aboutthe first turbine shell element and the recesses are circumferentiallyspaced about the second turbine shell element in corresponding positionsto the protuberances.
 12. The method of claim 10, wherein theprotuberances and the recesses are provided at substantiallysemi-toroidal radially outer portions of the first turbine shell elementand the second turbine shell element, respectively.
 13. The method ofclaim 10, wherein the protuberances and the recesses are provided atplanar portions of the first turbine shell element and the secondturbine shell element, respectively.
 14. The method of claim 1, whereinsaid connecting comprises welding the first turbine shell element to thesecond turbine shell element.
 15. The method of claim 1, wherein saidconnecting comprises sonically welding the first turbine shell elementto the second turbine shell element.
 16. The method of claim 1, furthercomprising forming the first turbine component separately from thesecond turbine component.
 17. The method of claim 1, wherein the firstturbine shell element and the second turbine shell element are connectedto one another without mechanical fasteners.
 18. A turbine assemblyhaving a rotational axis for a hydrokinetic torque converter, theturbine assembly comprising: a first turbine component comprising apolymeric first turbine shell element and first turbine blades connectedto the first turbine shell element; and a second turbine componentcomprising a second turbine shell element and second turbine bladesconnected to the second turbine shell element, wherein the first turbineshell element is fixedly secured by a connection to the second turbineshell element in a coaxial relationship about the rotational axis sothat the first and second turbine shell elements collectively provide aturbine shell of the turbine assembly, wherein the connection comprisesa weld, an adhesive bond, or a combination comprising a weld and anadhesive bond.
 19. The turbine assembly of claim 18, wherein the firstturbine shell element and the second turbine shell element are connectedto one another without mechanical fasteners.
 20. (canceled)
 21. A methodof making a hydrokinetic torque converter, the method comprising:providing a first turbine component comprising a polymeric first turbineshell element and first turbine blades connected to the first turbineshell element; providing a second turbine component comprising a secondturbine shell element and second turbine blades connected to the secondturbine shell element; connecting the first turbine shell element to thesecond turbine shell element to fixedly secure the first and secondturbine components to one another in a coaxial relationship about therotational axis so that the first and second turbine shell elementscollectively provide a turbine shell of a turbine assembly, saidconnecting comprising welding, adhesive bonding, or a combinationcomprising welding and adhesive bonding of the first turbine shellelement to the second turbine shell element; operatively securing theturbine assembly to an impeller assembly comprising an impeller shellwhereby the turbine assembly is coaxially aligned with andhydro-dynamically drivable by the impeller assembly; operativelyconnecting the turbine assembly to a turbine hub; operatively connectinga torsional vibration damper to the turbine hub; and operativelyconnecting the torsional vibration damper to a lockup clutch that ismovable into an out of locking engagement with a casing of thehydrokinetic torque converter, the casing being non-rotatable relativeto the impeller shell.
 22. (canceled)
 23. A hydrokinetic torqueconverter having a rotational axis, the hydrokinetic torque convertercomprising: a turbine assembly comprising a first turbine componentcomprising a polymeric first turbine shell element and first turbineblades connected to the first turbine shell element; and a secondturbine component comprising a second turbine shell element and secondturbine blades connected to the second turbine shell element, whereinthe turbine assembly is made by the method of claim 1; an impellerassembly operatively connected to the turbine assembly, the impellerassembly comprising an impeller shell, wherein the turbine assembly iscoaxially aligned with and hydro-dynamically drivable by the impellerassembly; a turbine hub operatively connected to the turbine assembly; atorsional vibration damper operatively connected to the turbine hub; anda locking clutch operatively connected to the torsional vibration damperand movable into an out of locking engagement with a casing of thehydrokinetic torque converter, the casing being non-rotatable relativeto the impeller shell.